A community outbreak of Legionnaires' disease linked to hospital cooling towers: an epidemiological method to calculate dose of exposure.

BACKGROUND: From July to September 1994, 29 cases of community-acquired Legionnaires' disease (LD) were reported in Delaware. The authors conducted an investigation to a) identify the source of the outbreak and risk factors for developing Legionella pneumophila serogroup 1 (Lp-1) pneumonia and b) evaluate the risk associated with the components of cumulative exposure to the source (i.e. distance from the source, frequency of exposure, and duration of exposure). METHODS: A case-control study matched 21 patients to three controls per case by known risk factors for acquiring LD. Controls were selected from patients who attended the same clinic as the respective case-patients. Water samples taken at the hospital, from eight nearby cooling towers, and from four of the patient's homes were cultured for Legionella. Isolates were subtyped using monoclonal antibody (Mab) analysis and arbitrarily primed polymerase chain reaction (AP-PCR). RESULTS: Eleven (52%) of 21 case-patients worked at or visited the hospital compared with 17 (27%) of 63 controls (OR 5.0, 95% CI : 1.1-29). For those who lived, worked, or visited within 4 square miles of the hospital, the risk of illness decreased by 20% for each 0.10 mile from the hospital; it increased by 80% for each visit to the hospital; and it increased by 8% for each hour spent within 0.125 miles of the hospital. Lp-1 was isolated from three patients and both hospital cooling towers. Based on laboratory results no other samples contained Lp-1. The clinical and main-tower isolates all demonstrated Mab pattern 1,2,5,6. AP-PCR matched the main-tower samples with those from two case-patients. CONCLUSION: The results of our investigation suggested that the hospital cooling towers were the source of a community outbreak of LD. Increasing proximity to and frequency of exposure to the towers increased the risk of LD. New guidelines for cooling tower maintenance are needed. Knowing the location of cooling towers could facilitate maintenance inspections and outbreak investigations.

Preventable disease in correctional facilities. Desmoteric foodborne outbreaks in the United States, 1974-1991.

BACKGROUND: Various disease outbreaks have been reported among prisoners. Recent foodborne outbreaks in correctional facilities in Georgia and Delaware prompted us to review the epidemiological characteristics of such outbreaks reported in the United States. METHODS: Foodborne outbreaks reported to the Centers for Disease Control and Prevention as part of routine surveillance from 1974 to 1991 were examined to identify outbreaks in jails, prisons, correctional facilities, and juvenile detention centers. Outbreak sizes, temporal trends, food vehicles, pathogens, and hygienic transgressions were analyzed. RESULTS: Eighty-eight desmoteric foodborne outbreaks involving 14307 cases of illness were reported from 31 states and territories. The mean outbreak size was 163 cases, compared with a mean of 31 cases for the 9107 reported outbreaks not involving prisoners. No fatalities among prisoners were reported. No pathogen was identified in 47 (53%) of the 88 outbreaks Salmonella species accounted for 15 (37%) of 41 outbreaks of known cause from 1974 to 1991, Clostridium perfringens for 14 (34%), and Staphylococcus aureus for 9 (22%). Fourteen of 15 Salmonella outbreaks occurred from 1984 to 1991. Food vehicles were reported for 63 (72%) of the outbreaks. Beef and poultry each were implicated in 9 (14%) of these, followed by fish or poultry salads and Mexican food, which accounted for 6 outbreaks (10%). Food-handling errors were reported for 69 (78%) of the 88 outbreaks. Improper food storage was reported in 62 (90%) of these. CONCLUSIONS: Foodborne outbreaks are reported regularly from correctional facilities in the United States. Outbreaks caused by Salmonella species, a special threat to prisoners with human immunodeficiency virus infection, seem to be increasing. Food production in correctional facilities should meet minimum safety standards, including sufficient refrigeration facilities, training of food handlers, and exemption of ill food handlers from work.

Fatal injury surveillance report, Delaware, 1990. Head and spinal cord injuries.

The Delaware Disabilities Prevention Program is funded through a five-year Centers for Disease Control and Prevention (CDC) grant to prevent primary and secondary disabilities associated with mental retardation and low socioeconomic status; head and spinal cord injuries; and sickle cell disease. This report focuses on fatal head and spinal cord injuries. Death certificates and autopsy reports from 1990 were the data sources used for this study. In 1990, 122 fatal head injuries and 20 fatal spinal cord injuries occurred among Delaware residents. Eight of these individuals experienced both head and spinal cord injuries. Motor vehicle crashes caused the majority of both head and spinal cord deaths. Suicides, homicides, and falls were the other major causes of fatal head injuries. Deaths are only the tip of the injury iceberg. Head and spinal cord injuries can cause lifelong disabilities affecting family, friends, and the entire community.

An analysis of lung cancer on a microgeographical level.

Mortality from cancers of the lung-bronchus-trachea show large variations in geographical distribution within the United States. Jefferson County, Kentucky shows significantly high mortality rates for this type of cancer. The focus of this study was to divide the country into small homogeneious areas to determine if there are geographical variations of mortality within the county as a whole. The results indicate that two areas of the county consistently show excess mortality for this particular type of cancer. Several possible explanations of the variations within the county are also explored.